The invention relates generally to a device for the opening and re-closing of containers, and more particularly, to flat, gabled, composite containers. The device of the present invention has a pouring aperture with a pouring nozzle formed thereon. There is a base having a flange enclosing the pouring aperture, for the attachment of the device to the surface of the container. A cover is hinged to the base, and an opening element is connected to the cover. The opening element is disposed to move in a guide in the cover, and is adapted to pierce the subjacent container material underlying the base during the opening operation. The invention also relates to the use of such a device with a flat, gabled, composite container and to flat, gabled, composite containers prepared for the application of said device.
Many constructions of parallelipipedic flat, gabled, composite containers are known. They are mainly used in the field of liquid packaging in connection with cold, cold-sterile, hot, and aseptic fillings. As a general rule, the packages cannot be re-closed once opened. In the case of flat, gabled, composite containers of the kind specified, it has already been suggested to place on the container gable, a pouring element which is provided with a corresponding cover (EP 0 577 865 A1). In order to weaken the gable material, a peripherally extending parting line is provided in the zone of the cardboard layer and the outer PE layer of the composite material. An opening element, connected to the cover and corresponding to the shape of the peripherally extending parting line, is forced through this weakened area of the container. After the container has been pierced, the pouring opening is accessed by hinging the cover open. The opening element and the piece of container composite disposed thereon will remain jointly hinged open, allowing the contents of the container to pass through the pouring opening. This prior art device is disadvantageous, as droplets of the contents of the container may remain on the piece of container composite hinged open together with the cover and then drip down onto the table or floor during the pouring operation, thereby reducing the efficient operation of the known device. This is particularly problematic in the case of fruit juices containing sugar, as the PE foil utilized in such packages tends to tear irregularly at the edges. Moreover, the re-closing of the device may lead to leakage, since the irregular tearing edge of the PE foil may result in jamming in the pouring aperture when the cover is closed. In addition to functional problems, the piece of container composite removed with the open cover makes for an unattractive appearance.
Therefore, one aspect of the present invention is to provide an improved device for the opening and re-closing of containers of the type described above, wherein the clean opening and re-closing of the device is ensured and high sealing tightness is achieved in the container. In addition, consumers require a device that is simple to operate, fully functional during the opening operation and attractive in appearance. This problem is solved by the device of the present invention, wherein the opening is constructed in two parts; mainly a pressure plate and a piercing ring, and wherein after opening the container, the piercing ring remains in the base.
The device according to the present invention can be put into effect with any kind of flat, gabled, composite container. However, it is particularly convenient if the flat, gabled, composite container to which the device is applied, has a peripherally extending weakening line, corresponding to the contour of the desired pouring opening and disposed in the zone of the subsequent pouring aperture. A flat, gabled, composite container can also have a supporting layer formed with a recess, which is disposed in the zone of the subsequent pouring aperture, corresponds to the contour of the desired pouring opening, and is sealed over with at least one PE layer.
According to one embodiment of the present invention, the underside of the pressure plate may have at least one peripherally extending web for receiving the piercing ring. Such a web can be disposed both in the interior and also around the exterior of the piercing ring. In another embodiment, two concentrically disposed webs could be provided whose spacing corresponds precisely to the thickness of the piercing ring. Alternatively, the cover and/or the opening element may possess a peripherally extending groove for receiving the piercing ring.
Since the opening element is preferably disposed displaceably in the cover, the device may also include at least one stop to limit the movement of the opening element. During the opening operation, the stop can reliably prevent the opening element from breaking away from the cover and entering the inside of the container. Another stop may be employed to affix the opening element to the cover after the container has been opened.
In another embodiment of the present invention, the piercing ring may have teeth to aid in piercing the container. The teeth may be arranged to produce a puncture of specific shape. Alternatively, a cutting edge may be substituted for the teeth. The user handles these alternative constructions of the opening element in an identical manner as the embodiments previously described. The pressing of the opening element into the closure member separates the section of composite material surrounding the weakening line and the section of PE foil sealed over the recess from the remainder of the container composite. The sections of composite and PE foil are then forced into the interior of the container. The teeth disposed on the piercing ring preferably do not extend completely around its periphery. This allows a section of both the composite material and the PE foil to remain attached, thus preventing the sections from entering the contents of the container. Allowing the sections to completely disengage from the container and enter its contents should be avoided, as problems may be caused during pouring if the freely floating sections completely or partially block the pouring aperture, or pass through the pouring aperture to a receptacle.
In a preferred construction of the device of the present invention, the piercing ring remains in the base after the opening operation. When the cover is hinged open the pressure plate is separated from the piercing ring, so that the pressure plate remains in the cover. To ensure the reliable separation and final location of these components, the outer surface of the piercing ring may also contain retaining elements. These retaining elements may take the form of projections and/or beads, for example, and assist in retaining the piercing ring in the base.
As is known from the earlier described prior art, in a preferred embodiment of the present invention, the cover is pivotally connected to the base. Preferably, the pivotal connection also has means for securing the cover in its opened position. This is particularly convenient, since it precludes the cover from inadvertently pivoting toward its closed position and inhibiting the flow of the contents from the package during the pouring operation.
In a preferred embodiment of the present invention, the cover and the opening element inserted therein, may form a flush surface when in the transport (closed) position. A flush surface provides for an attractive appearance and prevents the collection of dust or dirt above the opening element.
Although various shapes are possible, for ease of manufacture the pouring aperture and the piercing ring preferably have a round cross-section. A round cross-section also ensures that the force exerted on the opening element during the opening operation is evenly distributed around its periphery.
Preferably, the base, the cover, and the opening element are made of a plastic material. The base and the cover may be produced in one piece by injection molding. The opening element can be produced separately, in two parts, and inserted in the cover prior to application to the container.